Method of forming a wrap-around contact on a semiconductor device

ABSTRACT

Techniques and methods related to forming a wrap-around contact on a semiconductor device, and apparatus, system, and mobile platform incorporating such semiconductor devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. National Phase patentapplication Ser. No. 15/026,822 filed on Apr. 1, 2016, now U.S. Pat. No.9,704,744, which claims benefit to International Patent Application No.PCT/US2013/0076694 filed on Dec. 19, 2013.

BACKGROUND

A typical metal-oxide-semiconductor field-effect transistor (MOSFET) mayinclude a semiconductor (for example, silicon), electrodes to contact asource region and a drain region, and an electrode to contact or couplewith a gate. A FinFET is a MOSFET built around a thin strip ofsemiconductor material (generally referred to as the fin) extendingupward from a plate shaped substrate. One end of the fin is the sourceregion, while the opposite end of the fin is the drain region. Themiddle area of the fin forms a channel region which is covered by a gatedielectric and a gate electrode. The conductive channel of the deviceresides on the outer sides of the fin beneath the gate dielectric.Specifically, current runs along and within both sidewalls of the fin(the sides perpendicular to the substrate surface) as well as along thetop of the fin (the side parallel to the substrate surface). Because theconductive channel of such configurations essentially resides along thethree different outer, planar regions of the fin, such a FinFET issometimes referred to as a trigate FinFET. Other types of FinFETconfigurations are also available, such as so-called double-gateFinFETs, in which the conductive channel principally resides only alongthe two sidewalls of the fin (and not along the top of the fin). Acomplimentary metal-oxide semiconductor (CMOS) has dual fins, one finfor a p-type transistor (the PMOS), and another fin for an n-typetransistor (the NMOS). The dual fins are separated by an insulatingoxide layer on an integrated circuit for example. Both the source anddrain regions of each fin may be covered with a contact connected todrive circuitry that delivers a drive current to and from the source anddrain regions. The drive current at the fin and conducted through thecontacts at the source and drain regions still may be increased.

BRIEF DESCRIPTION OF THE DRAWINGS

The material described herein is illustrated by way of example and notby way of limitation in the accompanying figures. For simplicity andclarity of illustration, elements illustrated in the figures are notnecessarily drawn to scale. For example, the dimensions of some elementsmay be exaggerated relative to other elements for clarity. Further,where considered appropriate, reference labels have been repeated amongthe figures to indicate corresponding or analogous elements. In thefigures:

FIG. 1 is an upper perspective view of a dual complimentary metal-oxidesemiconductor device;

FIG. 2 is a flow chart for fabricating the semiconductor devices;

FIGS. 3-6 are cross-sectional views of example semiconductor devices asparticular fabrication operations are performed;

FIG. 7 is another flow chart for fabricating the semiconductor devices;

FIG. 8 is an illustrative diagram of a mobile computing platformemploying an integrated circuit with transistors having a wrap-aroundcontact on fins of the transistor; and

FIG. 9 is a functional block diagram of a computing device, all arrangedin accordance with at least some implementations of the presentdisclosure.

DETAILED DESCRIPTION

One or more implementations are now described with reference to theenclosed figures. While specific configurations and arrangements arediscussed, it should be understood that this is done for illustrativepurposes only. Persons skilled in the relevant art will recognize thatother configurations and arrangements may be employed without departingfrom the spirit and scope of the description. It will be apparent tothose skilled in the relevant art that techniques and/or arrangementsdescribed herein may also be employed in a variety of other systems andapplications other than what is described herein.

Reference is made in the following detailed description to theaccompanying drawings, which form a part hereof, wherein like numeralsmay designate like parts throughout to indicate corresponding oranalogous elements. It will be appreciated that for simplicity and/orclarity of illustration, elements illustrated in the figures have notnecessarily been drawn to scale. For example, the dimensions of some ofthe elements may be exaggerated relative to other elements for clarity.Further, it is to be understood that other implementations may beutilized and structural and/or logical changes may be made withoutdeparting from the scope of claimed subject matter. It should also benoted that directions and references, for example, up, down, top,bottom, and so on, may be used to facilitate the discussion of thedrawings and are not intended to restrict the application of claimedsubject matter. Therefore, the following detailed description is not tobe taken in a limiting sense and the scope of claimed subject matterdefined by the appended claims and their equivalents.

In the following description, numerous details are set forth, however,it will be apparent to one skilled in the art, that the presentinvention may be practiced without these specific details. In someinstances, well-known methods and devices are shown in block diagramform, rather than in detail, to avoid obscuring the present invention.Reference throughout this specification to “an implementation” or “inone implementation” means that a particular feature, structure,function, or characteristic described in connection with theimplementation is included in at least one implementation of theinvention. Thus, the appearances of the phrase “in an implementation” invarious places throughout this specification are not necessarilyreferring to the same implementation of the invention. Furthermore, theparticular features, structures, functions, or characteristics may becombined in any suitable manner in one or more implementations. Forexample, a first implementation may be combined with a secondimplementation anywhere the two implementations are not specified to bemutually exclusive.

The terms “coupled” and “connected,” along with their derivatives, maybe used herein to describe structural relationships between components.It should be understood that these terms are not intended as synonymsfor each other. Rather, in particular implementations, “connected” maybe used to indicate that two or more elements are in direct physical orelectrical contact with each other. “Coupled” my be used to indicatethat two or more elements are in either direct or indirect (with otherintervening elements between them) physical or electrical contact witheach other, and/or that the two or more elements co-operate or interactwith each other (for example, as in a cause and effect relationship).

The terms “over,” “under,” “between,” “on”, and/or the like, as usedherein refer to a relative position of one material layer or componentwith respect to other layers or components. For example, one layerdisposed over or under another layer may be directly in contact with theother layer or may have one or more intervening layers. Moreover, onelayer disposed between two layers may be directly in contact with thetwo layers or may have one or more intervening layers. In contrast, afirst layer “on” a second layer is in direct contact with that secondlayer. Similarly, unless explicitly stated otherwise, one featuredisposed between two features may be in direct contact with the adjacentfeatures or may have one or more intervening features. Additionally, theterms “under” or “over” or “down” or “up” and/or similar terms relatingto relative position are meant to express internal relative positioningbetween components and do not necessarily mean upward or downwardrelative to the earth unless stated otherwise.

Devices, microprocessors, apparatuses, computing platforms, and methodsare described below related to forming a wrap-around contact on asemiconductor device.

Many semiconductor devices have multiple fins, which may be positionedrelatively close to each other on a wafer. One such example is acomplementary metal oxide semiconductor (CMOS) device that may have dualfins including a p-type fin adjacent an n-type fin separated by aninsulation layer. The CMOS may be adjacent other CMOS devices such thata fin on one device is relatively close to a fin on another device. Thesource and drain regions on the fins are often covered by a contact forapplying a drive current. Increasing the area that the contact covers,and at a sufficient thickness to correctly set the junctionworkfunction, reduces the contact resistance thereby increasing thedrive current when the source and drain have the same voltage. When morecurrent passes through the contact, the transistor is more efficient,and the total power for operating the transistor may be reduced or thedrive current may be increased.

On a 3-D tri-gate transistor with fins such as a CMOS and otherintegrated circuits, upstanding fins may be separated by a trench thatmay be at least partially filled with an insulating material. The finsare referred to as tri-gate or 3-D because the top surface and bothopposite sidewalls of the fin each form a gate (each surface is a gate).The source and drain regions of the fin may generally maintain thefin-like shape with a top and two sidewalls, and the contact materialmay be placed over the fin at these regions. Contact material may bedeposited either before or after the insulation material is deposited inthe trenches. The contact material is often deposited using physicalsputtering, which is a line of sight deposition. This makes it difficultto provide sufficient contact material on the sidewalls of the finswithin the trenches in order to efficiently expand the area of thecontact to all three surfaces of the fins. Specifically, the sputteredmaterial is aimed directly toward the top of the fins (where the top ofthe fins are normal or flat relative to the direction of sputter). Thus,fin sidewalls will not receive sufficient metal thickness to adequatelyset the junction workfunction, and the current flow is largelyrestricted to the area on the top of the fin.

The method described herein solves this difficulty by sputtering aninitial contact layer onto the fins (also referred to herein as theupstanding or upwardly extending semiconductor bodies). Then aresputtering operation is performed to redistribute contact material ofthe initial contact layer onto the sidewalls of the semiconductorbodies. This provides a sufficient, more uniform, thickness of thecontact on the sidewalls of the semiconductor bodies to provide asignificant increase in drive current through the contact layer.

Referring to FIG. 1, various implementations described herein overcomethe difficulties mentioned above, and in one illustrated example, anintegrated circuit may have a transistor or semiconductor device 100provided with upstanding or upwardly extending semiconductor bodies 102and 104, also referred to as semiconductor fins, fin portions, or cores.It should be noted that for the purposes of the method described hereinthe semiconductor body is not necessarily limited to a fin shape whereits height is greater than its width, and so forth. The semiconductorbodies 102 and 104 may be provided over a wafer or substrate 106, madeof silicon (Si) in this example. The semiconductor bodies 102 and 104may be made of Si, SiGe, or Ge. In one form, the semiconductor bodies102 and 104 are substantially a uniform material with a semiconductormaterial at the core of the fin or semiconductor body. In otheralternatives, the fins or semiconductor bodies may have different layerswhich may include a semiconductor layer and/or a semiconductor core. Ineither case, the semiconductor bodies conduct current in a channeldirection along the length of the fin or semiconductor body generallytransverse to the height of the fin or semiconductor body (or in otherwords between the source region 130 or 132 and drain region 134 or 136in FIG. 1).

More specifically, semiconductor device 100 may be formed on a wafer,and in some forms may constitute one die, or a part of a die, of manydies of a wafer. The semiconductor device may be one of a plurality ofsemiconductor devices on the wafer whether tens, hundreds, thousands,millions, or billions of semiconductor devices on the wafer. Also, thesemiconductor device 100 may be a transistor or other electroniccomponent, and may part of an integrated circuit formed by the wafer, ormay be singulated to form a discrete chip. Semiconductor device 100 maybe a microelectronic device included in any device having a circuit witha logic gate electrode, such as a metal-oxide semiconductor field-effecttransistor (MOSFET) gate electrode (such as, logic circuitry). Forexample, microelectronic device 100 may be a microprocessor, a staticrandom access memory (SRAM) circuit, or a portion of an SRAM cachememory of a microprocessor, or the like to name a few non-limitingexamples.

Semiconductor device 100 may be a non-planar, 3-D finFET with at leastone p-type semiconductor body or fin 102 and at least one n-typesemiconductor body or fin 104. The fins may be arranged in manydifferent orientations on the wafer. Thus, in one form, fins of likecarrier charge may be grouped together, or alternatively, oradditionally, fins of different carrier charges may be alternating orpaired with one p-type fin adjacent an n-type fin as with complementarymetal-oxide semiconductors (CMOS). Thus, the semiconductor device may bepart of an integrated circuit with many such semiconductor devices, ormay be an isolated semiconductor device on the integrated circuit.Otherwise, the semiconductor device may be on its own chip or die forexample. With the integrated circuit, the semiconductor device may stillbe isolated where a dual pair of single p-type or n-type fin have theirown gate without any relatively near semiconductor devices on thecircuit, or the semiconductor device may be nested within a long line or2D network of similar, parallel semiconductor devices.

Thus, the basic transistor elements of the semiconductor device 100include, as mentioned above, the substrate 106, upstanding semiconductorbodies or fins 102 and 104 formed over or on the substrate 106, and thatare separated by an insulation layer 118 (also referred to as trenchisolation or simply insulation or an isolation). It also may be asemiconductor on insulator (SOI) structure or may have a semiconductortrench insulation (STI) structure. The semiconductor devices 102 and 104may be formed as extensions of the substrate or may be part of anadditional, separate substrate layer 128 shown in dashed line. A gateelectrode 120 extends over, and transverse to, the semiconductor bodies102 and 104. Dielectric layers 122 may be disposed over channel regionsof the semiconductor bodies 102 and 104 and underneath the gateelectrode 120. The semiconductor bodies 102 and 104 also have sourceregions 130 and 132, and drain regions 134 and 136. A contact or contactlayer 110 is positioned over each source and drain region. The contactmay be connected to a power source by way of metal interconnects andvias.

The semiconductor device 100 may be an isolated transistor where thereis one gate electrode between trench isolation along the current flowdirection. Otherwise, the semiconductor device 100 may be a portion ofan elongated circuit in the fin direction. In other words, in thecurrent flow (or along the fin) direction, nested transistors may beprovided where a single fin contains more transistors between the trenchisolation.

The semiconductor bodies may or may not have cladding layers, which maybe maintained at the channel region, and/or may extend to the source anddrain regions. In this case, the contact 110 may cover the claddinglayer as well as the semiconductor bodies 102 and 104 thereunder, and atthe source and drain regions. 130, 132, 134, and 136.

Each semiconductor body has a top or upper surface 112 and oppositesidewalls 114 and 116 that extend transverse to the top 112 and from abottom 124 of a trench 126 formed between the semiconductor bodies 102and 104.

The contact layer 110 may extend over all three sides of thesemiconductor bodies 102 and 104, and along the bottom 124 of the trench126. The contact layer may be continuous over any number of aligned orarrayed semiconductor bodies. Those semiconductor bodies at the end of awafer or that are relatively isolated from an adjacent semiconductorbody where the trench may flatten out, may have the contact layer end asit extends away from the semiconductor body and before reaching the endof the wafer or the contact at an adjacent semiconductor body.

Referring now to FIG. 2, a method 200 of forming a wrap-around contactfor a semiconductor device, and more particularly to the use of aresputtering operation to form a contact layer with a more uniformthickness on all three sides of the semiconductor bodies is arranged inaccordance with at least some implementations of the present disclosure.In the illustrated implementation, process 200 may include one or moreoperations, functions or actions as illustrated by one or more ofoperations 202 and 204. Implementations herein, however, may include anynumber of operations such that some of the operations may be skipped orthe like. Further, various implementations may include additionaloperations not shown for the sake of clarity. Also, in general, with thetechniques described with respect to FIG. 2, process 200 provides anexample method for forming the semiconductor structure of any of theimplementations herein; however, other methods may be available forforming such structures.

The process 200 may include an operation “DEPOSITING A CONTACT MATERIALOF AN INITIAL CONTACT LAYER ON A SOURCE REGION OR DRAIN REGION OR BOTHOF AT LEAST TWO SEMICONDUCTOR BODIES SEPARATED FROM EACH OTHER BY ATRENCH AND DISPOSED OVER A SUBSTRATE” 202. As mentioned below, theinitial contact layer may be mainly deposited on the top of thesemiconductor bodies and the bottom of the trenches.

The process 200 also may include an operation “RE-SPUTTERING THE CONTACTMATERIAL OF THE INITIAL CONTACT LAYER TO REDISTRIBUTE AT LEAST SOME OFTHE CONTACT MATERIAL ONTO A PORTION OF THE SEMICONDUCTOR BODIES WITHINTHE TRENCH” 204. In one particular example, the contact material may bebombarded by a plasma with wafer bias so that the impact of the plasmaon the contact material at the bottom of the trench and the top of thesemiconductor bodies causes at least part of the contact material tomove to the sidewalls of the semiconductor bodies.

Referring now to FIGS. 3-7, a detailed process 700 is explained inconjunction with the semiconductor device 300 shown at FIGS. 3-6 invarious states during fabrication of the semiconductor bodies, such asfor semiconductor device 100. The cross-sections extend generallyparallel to the gate electrode and transverse to the semiconductorbodies (or fins) to provide a section through the source or drainregions of each of the semiconductor bodies shown. Referring to FIG. 3,in an initial stage, the operation 700 may include “form semiconductorbodies on the semiconductor device” 702. The semiconductor device 300may initially have a semiconductor wafer or substrate 302, similar tosubstrate 106 for instance, and may be composed of undopedmonocrystalline silicon (Si) in some forms. While the semiconductorsubstrate 302 here is an intrinsic (for instance, undoped) siliconsubstrate, in other forms the substrate 302 may be doped to a p type orn type conductivity.

The semiconductor bodies 304 and 306 may be made of Si, SiGe, or Ge, andeach semiconductor body may have a sidewall 308 and 310 extending from abottom 312 of a trench 314 up to a top or upper surface 316 of thesemiconductor body 304 or 306. Due to manufacturing tolerances, thesidewalls 308 and 310 may or may not extend completely perpendicular tothe upper surface 318 of the substrate 302, and may be approximatelytransverse, and in the illustrated form, may have an angle of about 10degrees. At least initially, the semiconductor bodies 304 and 306 may beformed in a continuous line of the same material to form the source,channel, and drain region of the semiconductor body for each device ortransistor. By one approach, the semiconductor bodies or fins 304 and306 may be about 30 to 70 nm high.

The process 700 may continue with “form source and drain regions of thesemiconductor bodies” 704. This may include finalizing the source anddrain regions as needed including any material etching, diffusion,material replacement, and so forth to provide the source and drainregions with a desired material if it is to be different from thechannel region of the semiconductor bodies 304 and 306. This operationmay also include doping such as by using implantation and annealing orindiffusion from a solid source. The source and drain regions may thenbe doped appropriately to obtain the desired p-type or n-typesemiconductor body. By one approach, the source/drain regions have adoping concentration of between approximately 1×10¹⁹ to 1×10²′atoms/cm³, and in one form, at least approximately 5×10²⁰ atoms/cm³. Thesource/drain regions can be formed of uniform concentration or caninclude sub-regions of different concentrations or doping profiles, suchas tip regions (for example, source/drain extensions). In one form, whensemiconductor device 100 or 300 is a symmetrical transistor, the sourceand drain regions will have the same doping concentration profile. Inanother form, transistor 100 or 300 is an asymmetrical transistor, andthe source region and drain region may have varied doping in order toobtain particular electrical characteristics.

Referring to FIG. 3, process 700 may then continue with “deposit theinitial contact layer” 706. This may include using radio frequencyphysical vapor deposition (RFPVD) in a sputter chamber such as theApplied Materials “Aura” PVD deposition chamber. In this process, aplasma gas, such as argon, is entered into the chamber under vacuum andbombarded onto a titanium target plate held at a certain distanceopposing the wafer or substrate 302 holding the semiconductor device(s).The bombarded of titanium ions and atoms are directed in straight,line-of-sight fashion to the semiconductor devices held on a pedestal inthe chamber. Power for deposition is provided both by a 40 MHz RFgenerator between 2000 W and 7500 W, and by a DC generator between 500and 2500 W. Deposition is performed between 50 and 100 mTorr atapproximately room temperature.

The initial sputter operation may also include “provide sacrificialportion” for the initial contact layer. Thus, as shown on FIG. 4, aninitial contact layer 400 may include sacrificial portions 402 at thetop of the semiconductor bodies 304 and 306, and sacrificial portions404 at the bottom of the trenches. Sufficient contact material 406 maybe sputtered so that the total height of the initial contact layer atthe top of the semiconductor body 304 or 306, and at the bottom of thetrench 314, is about 3 to 15 nm tall, including a sacrificial portionthat is about 5 to 10 nm tall, when this operation is complete. Thesacrificial portion may be about 10 to 20 nm tall prior to theresputtering portion of layer deposition.

In the next operation of “re-sputter the contact material” 710, thechamber is refilled with the plasma, or argon gas, but this time withoutsignificant voltage applied between the target plate and the pedestal.Bias for resputtering is provided by a 13.56 MHz generator with 100W-1000 W RF power, and resputtering is performed between 1 and 10 mTorr.As shown in FIG. 4, the plasma will be directed toward the semiconductordevice 300, and as shown by the thick arrows, the impact of the argonions on the metal initial contact layer will cause the contact material,such as in atom or ion form, to redistribute, and this includes motionor redistribution toward the sidewalls 308 and 310. The plasma isdirected toward the semiconductor device because the bias reverses thevoltage between the target electrode and wafer, so the Ar plasma isdirected at the wafer instead (or in other words, the wafer becomes thetarget).

Thus, with this operation, the method 700 uses extra sputtered metal asthe protection or sacrificial layer 402 or 404 to avoid sputtering (orin other words, etching away) the semiconductor bodies 304 or 306. Thisis necessary due to the physical nature of the resputtering. Physicalresputtering rate will increase in areas of high curvature, such as thetop corners of the semiconductor bodies 304 or 306, and will not beselective to the Si, SiGe, or Ge in those bodies. In the presentexample, the resputtering will etch away 10 nm of the initial contactlayer, and deposit about 1 to 5 nm of contact material at the sidewalls308 and 310.

As shown on FIG. 5, the resulting resputter-formed contact layer (orsubsequent or final contact layer) 500 is substantially more uniformthan from the initial contact layer 402. This provided about a 10-20%increase in drive power provided to the semiconductor bodies 304 and 306compared to the identical structure covered with PVD deposition alone.This increase will be proportional to the semiconductor body area thatwas previously uncovered.

Referring to FIG. 6, an alternative resputtered contact layer 600 isshown that may more accurately depict the final profile of the contactlayer 600. In this case, the resputtering forms a slight overhang 602and rounded upper surface 604. This profile is characteristic of theresputter process, due to the vectors of physically resputtered atomsand their re-attachment to the existing structure.

Process 700 may then proceed with “deposit insulation layer” 712, suchas trenches 312 when desired, such as with shallow trench isolation(STI) regions may be deposited on the contact layer 500 or 600 in thetrenches 312, and may be formed of a dielectric or electricallyinsulative material. The electrically insulative material may includeany suitable material for shallow trench isolation (STI). In some forms,the electrically insulative material for the insulation layer mayinclude dielectric materials known for their applicability in integratedcircuit structures, such as low-k dielectric materials. Examples ofdielectric materials that may be used for insulation layer 402 include,but are not limited to, silicon oxide, carbon doped oxide (CDO), siliconnitride, organic polymers such as perfluorocyclobutane orpolytetrafluoroethylene, fluorosilicate glass (FSG), and organosilicatessuch as silsesquioxane, siloxane, or organosilicate glass.

Contact to back-end vias and interconnects is then facilitated bydeposition of a low resistance contact metal such as Al, W, Co, or Cu,and then planarized to the isolation to create individual, filledcontact trenches.

The process 700 may continue with an operation to “form electrodes” 714.Thus, a gate may also be formed and may include a gate dielectric suchas gate dielectric 122 (FIG. 1) and a gate electrode 120 (FIG. 1). Thismay include forming the gate dielectric layer 122 at the channel regionsof the semiconductor bodies. The gate electrode 120 may be formed on thegate dielectric 122, and may be composed of at least one p-typeworkfunction metal or n-type workfunction metal, depending on whetherthe transistor is to be a PMOS (for example, p-type) or an NMOS (forexample, n-type) transistor. By one form, gate electrode 120 is formedto a thickness sufficient to completely cover or surround the channelregions of the semiconductor bodies 102 and 104, and gate dielectriclayers 122 as shown in FIG. 1.

In some forms, a pair of spacers 121 (shown roughly in dashed line) maybracket the gate electrode 120, for example, on opposing surfaces of thesidewalls 119 of the gate electrode 120 (the sides where the fins areintersecting the gate electrode 120). The spacers may be formed from amaterial such as silicon nitride, silicon oxide, silicon carbide,silicon nitride doped with carbon, and silicon oxynitride. Processes forforming spacers may generally include deposition and etching processesand/or other well-known techniques. The sacrificial layer describedherein will also protect the spacers from physical impact from theresputter operation during contact metal deposition because the spacersare also exposed to the sputtering process. Thus, if an insufficientsacrificial metal layer from the initial contact deposition covers thespacer, the resputtering process can resputter the spacer material aswell. This is true even though the spacer is positioned on therelatively vertical sidewalls of the gate electrode 120.

The process 700 also optionally includes “complete integrated circuit”716 when the semiconductor device 100 or 300, for example, is one ofmany such devices for an integrated circuit rather than as an isolatedtransistor. In this case, “back end” techniques can be utilized to formmetal contacts, metallization layers and interlayer dielectrics tointerconnect various transistors together into functional integratedcircuits, such as microprocessors.

While implementation of example process 200 and 700, may include theundertaking of all operations shown in the order illustrated, thepresent disclosure is not limited in this regard and, in variousexamples, implementation of processes 200 and 700 may include theundertaking of only a subset of the operations shown, operations can becombined together or sub-divided, and/or in a different order thanillustrated.

In addition, any one or more of the operations of FIGS. 2 and 7 may beundertaken in response to instructions provided by one or more computerprogram products. Such program products may include signal bearing mediaproviding instructions that, when executed by, for example, a processor,may provide the functionality described herein. The computer programproducts may be provided in any form of one or more computer readablemedia. Thus, for example, a processor including one or more processorcore(s) may undertake one or more of the example operations shown inFIGS. 2 and 7 in response to program code and/or instructions orinstruction sets conveyed to the processor by one or moremachine-readable media. In general, a machine-readable medium may conveysoftware in the form of program code and/or instructions or instructionsets that may cause any of the devices and/or systems to perform asdescribed herein.

FIG. 8 is an illustrative diagram of a mobile computing platformemploying an IC with transistors having an unrecessed field insulatorand thinner electrodes over the field insulator, arranged in accordancewith at least some implementations of the present disclosure. Mobilecomputing platform 800 may be any portable device configured for each ofelectronic data display, electronic data processing, wireless electronicdata transmission, or the like. For example, mobile computing platform800 may be any of a tablet, a smart phone, laptop computer, etc. and mayinclude a display screen 805, which in the exemplary implementation is atouchscreen (for example, capacitive, inductive, resistive, etc.touchscreen), a chip-level (SoC) or package-level integrated system 810,and a battery 815.

Integrated system 810 is further illustrated in the expanded view 820.In the exemplary implementation, packaged device 850 (labeled“Memory/Processor with Wrap-around Contacts on the Fins” in FIG. 8, andaccording to the implementations described herein) includes at least onememory chip (for example, RAM), and/or at least one processor chip (forexample, a microprocessor, a multi-core microprocessor, or graphicsprocessor, or the like) employing transistors with p-type and n-typecladded fins as discussed herein. In an implementation, the packagedevice 850 is a microprocessor including an SRAM cache memory employingtransistors with p-type and n-type cladded fins as discussed herein (forexample, the SRAM cache memory may include an inverter circuit employingtransistors as discussed herein).

An employed transistor may include a semiconductor device with asubstrate, a strained layer forming both p-type and n-type semiconductorbodies such as fins, and cladding layers over or on at least the n-typesemiconductor bodies, where the cladding layers are grown as describedherein. Packaged device 850 may be further coupled to (for example,communicatively coupled to) a board, a substrate, or an interposer 860along with, one or more of a power management integrated circuit (PMIC)830, RF (wireless) integrated circuit (RFIC) 825 including a wideband RF(wireless) transmitter and/or receiver (TX/RX) (for example, including adigital baseband and an analog front end module further comprises apower amplifier on a transmit path and a low noise amplifier on areceive path), and a controller thereof 835. In general, packaged device850 may be also be coupled to (for example, communicatively coupled to)display screen 805.

Functionally, PMIC 830 may perform battery power regulation, DC-to-DCconversion, etc., and so has an input coupled to battery 815 and with anoutput providing a current supply to other functional modules. Asfurther illustrated, in the exemplary implementation, RFIC 825 has anoutput coupled to an antenna (not shown) to implement any of a number ofwireless standards or protocols, including but not limited to Wi-Fi(IEEE 802.11 family), WiMAX (IEEE 802.16 family), IEEE 802.20, long termevolution (LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA,TDMA, DECT, Bluetooth, derivatives thereof, as well as any otherwireless protocols that are designated as 3G, 4G, 5G, and beyond. Inalternative implementations, each of these board-level modules may beintegrated onto separate ICs coupled to the package substrate ofpackaged device 850 or within a single IC (SoC) coupled to the packagesubstrate of the packaged device 850.

FIG. 9 is a functional block diagram of a computing device 900, arrangedin accordance with at least some implementations of the presentdisclosure. Computing device 900 may be found inside platform 800, forexample, and further includes a motherboard 902 hosting a number ofcomponents, such as but not limited to a processor 904 (for example, anapplications processor), which may incorporate transistors with claddedp-type and n-type semiconductor bodies as discussed herein, and at leastone communication chip 906. In implementations, at least one of theprocessor 904, one or more communication chips 906, or the like may bephysically and/or electrically coupled to motherboard 902. In someexamples, processor 904 includes an integrated circuit die packagedwithin the processor 904. In general, the term “processor” may refer toany device or portion of a device that processes electronic data fromregisters and/or memory to transform that electronic data into otherelectronic data that may be stored in registers and/or memory.

In various examples, one or more communication chips 906 may also bephysically and/or electrically coupled to the motherboard 902. Infurther implementations, communication chips 906 may be part ofprocessor 904. Depending on its applications, computing device 900 mayinclude other components that may or may not be physically andelectrically coupled to motherboard 902. These other components include,but are not limited to, volatile memory (for example, DRAM),non-volatile memory (for example, ROM), flash memory, a graphicsprocessor, a digital signal processor, a crypto processor, a chipset, anantenna, touchscreen display, touchscreen controller, battery, audiocodec, video codec, power amplifier, global positioning system (GPS)device, compass, accelerometer, gyroscope, speaker, camera, and massstorage device (such as hard disk drive, solid state drive (SSD),compact disk (CD), digital versatile disk (DVD), and so forth), or thelike.

Communication chips 906 may enables wireless communications for thetransfer of data to and from the computing device 900. The term“wireless” and its derivatives may be used to describe circuits,devices, systems, methods, techniques, communications channels, and soforth that may communicate data through the use of modulatedelectromagnetic radiation through a non-solid medium. The term does notimply that the associated devices do not contain any wires, although insome implementations they might not. Communication chips 906 mayimplement any of a number of wireless standards or protocols, includingbut not limited to those described elsewhere herein. As discussed,computing device 900 may include a plurality of communication chips 906.For example, a first communication chip may be dedicated to shorterrange wireless communications such as Wi-Fi and Bluetooth and a secondcommunication chip may be dedicated to longer range wirelesscommunications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, andothers.

As used in any implementation described herein, the term “module” refersto any combination of software logic and/or firmware logic configured toprovide the functionality described herein. The software may be embodiedas a software package, code and/or instruction set, and/or firmware thatstores instructions executed by programmable circuitry. The modules may,collectively or individually, be embodied for implementation as part ofa larger system, for example, an integrated circuit (IC), system on-chip(SoC), and so forth.

As used in any implementation described herein, the term “logic unit”refers to any combination of firmware logic and/or hardware logicconfigured to provide the functionality described herein. The“hardware”, as used in any implementation described herein, may include,for example, singly or in any combination, hardwired circuitry,programmable circuitry, state machine circuitry, and/or firmware thatstores instructions executed by programmable circuitry. The logic unitsmay, collectively or individually, be embodied as circuitry that formspart of a larger system, for example, an integrated circuit (IC), systemon-chip (SoC), and so forth. For example, a logic unit may be embodiedin logic circuitry for the implementation firmware or hardware of thesystems discussed herein. Further, one of ordinary skill in the art willappreciate that operations performed by hardware and/or firmware mayalso utilize a portion of software to implement the functionality of thelogic unit.

As used in any implementation described herein, the term “engine” and/or“component” may refer to a module or to a logic unit, as these terms aredescribed above. Accordingly, the term “engine” and/or “component” mayrefer to any combination of software logic, firmware logic, and/orhardware logic configured to provide the functionality described herein.For example, one of ordinary skill in the art will appreciate thatoperations performed by hardware and/or firmware may alternatively beimplemented via a software module, which may be embodied as a softwarepackage, code and/or instruction set, and also appreciate that a logicunit may also utilize a portion of software to implement itsfunctionality.

While certain features set forth herein have been described withreference to various implementations, this description is not intendedto be construed in a limiting sense. Hence, various modifications of theimplementations described herein, as well as other implementations,which are apparent to persons skilled in the art to which the presentdisclosure pertains are deemed to lie within the spirit and scope of thepresent disclosure.

The following examples pertain to further implementations.

By one implementation, a method of forming a semiconductor devicecomprises depositing a contact material of an initial contact layer on asource region or drain region or both of at least two semiconductorbodies and separated from each other by a trench and disposed over asubstrate. The method also comprises re-sputtering the contact materialof the initial contact layer to redistribute at least some of thecontact material onto at least one portion of the semiconductor bodieswithin the trench.

By other implementations, a method is provided where the semiconductorbodies have a top and sidewalls extending from, and transverse to, thetop, and the depositing operation comprises depositing the initialcontact layer at least on the top, and the re-sputtering redistributesthe contact material onto the sidewalls. The depositing operation alsocomprises depositing contact material at a bottom of the trench, andwhere re-sputtering redistributes at least some of the contact materialfrom the bottom of the trench onto the sidewalls of the semiconductorbodies. The method comprises forming a sacrificial portion of theinitial contact layer, and redistributing the sacrificial portion duringthe re-sputtering of the contact material, where the sacrificial portionadds about 10-20 nm to the height of the initial contact layer, thecontact material comprises titanium, and the contact layer at thesidewalls resulting after the resputtering is at least about 1-5 nmthick. Otherwise, re-sputtering comprises directing a plasma bombardmentmaterial toward the initial contact layer and on a biased wafer. Themethod also may comprise depositing the contact material on a surface ofa spacer disposed at a gate electrode intersecting the semiconductorbodies and while depositing the contact material of the initial contactlayer. The method comprises depositing a sufficient amount of thecontact material on the surface of the spacer to form a sacrificiallayer at the spacer to avoid damage to the spacer during re-sputtering.

By one approach, a semiconductor device comprises a substrate, at leasttwo semiconductor bodies separated from each other by a trench anddisposed over the substrate, and the semiconductor bodies have a sourceregion and a drain region separated by a channel region, and aresputter-formed contact layer on the semiconductor bodies and formed byre-sputtering an initial contact layer at least partially redistributedto a portion of the semiconductor bodies within the trench. The devicemay also have a gate dielectric layer disposed over the channel regionof the semiconductor bodies, and a gate electrode disposed over the gatedielectric layer.

By other approaches, the semiconductor device has semiconductor bodiesthat have a top and sidewalls extending from, and transverse to, thetop, and where the initial contact layer is disposed at least on thetop, and the resputter-formed contact layer is disposed at the sidewallswith contact material from the initial contact layer at the top.Otherwise, the semiconductor bodies have sidewalls extending from thetrench, the trench has a bottom, and where the initial contact layer isdisposed at the bottom of the trench, and where the resputter-formedcontact layer at the sidewalls is at least partially formed from contactmaterial from the bottom of the trench. By another aspect, the initialcontact layer comprises a sacrificial portion configured and arranged tobe redistributed during re-sputtering of the contact material from theinitial contact layer, and the sacrificial portion adds about 10-20 nmto the height of the initial contact layer, while the resputter-formedcontact layer is disposed at the sidewalls and has a thickness at thesidewalls of at least about 1-5 nm thick. Also, the contact materialcomprises titanium, and the re-sputter-formed contact layer is formed bya plasma bombardment material directed toward the initial contact layerand on a biased wafer. The semiconductor comprises a spacer disposed atthe gate electrode, the contact material is disposed at a surface of thespacer from the depositing of the contact material of the initialcontact layer, and the contact material has a sufficient amount on thesurface of the spacer to form a sacrificial layer at the spacer to avoiddamage to the spacer during re-sputtering.

By another aspect, a mobile computing platform comprises amicroprocessor, comprises a substrate, at least two semiconductor bodiesseparated from each other by a trench and disposed over the substrate,and the semiconductor bodies have a source region and a drain regionseparated by a channel region, and a resputter-formed contact layer onthe semiconductor bodies and formed by re-sputtering an initial contactlayer at least partially redistributed to a portion of the semiconductorbodies within the trench. The microprocessor may also have a gatedielectric layer disposed over the channel region of the semiconductorbodies, and a gate electrode disposed over the gate dielectric layer.The platform may also have a display screen communicatively coupled tothe microprocessor, and a wireless transceiver communicatively coupledto the microprocessor.

By other aspects, the platform has semiconductor bodies that have a topand sidewalls extending from, and transverse to, the top, and where theinitial contact layer is disposed at least on the top, and theresputter-formed contact layer is disposed at the sidewalls with contactmaterial from the initial contact layer at the top. Otherwise, thesemiconductor bodies have sidewalls extending from the trench, thetrench has a bottom, and where the initial contact layer is disposed atthe bottom of the trench, and where the resputter-formed contact layerat the sidewalls is at least partially formed from contact material fromthe bottom of the trench. By another aspect, the initial contact layercomprises a sacrificial portion configured and arranged to beredistributed during re-sputtering of the contact material from theinitial contact layer, and the sacrificial portion adds about 10-20 nmto the height of the initial contact layer, while the resputter-formedcontact layer is disposed at the sidewalls and has a thickness at thesidewalls of at least about 1-5 nm thick. Also, the contact materialcomprises titanium, and the re-sputter-formed contact layer is formed bya plasma bombardment material directed toward the initial contact layerand on a biased wafer. The platform comprises a spacer disposed at thegate electrode, the contact material is disposed at a surface of thespacer from the depositing of the contact material of the initialcontact layer, and the contact material has a sufficient amount on thesurface of the spacer to form a sacrificial layer at the spacer to avoiddamage to the spacer during re-sputtering.

In a further example, a microprocessor may include an SRAM cache memoryfurther having a transistor including any one of the above examplestructures.

In a still further example, a mobile computing platform may include anyof the example structures.

It will be recognized that the invention is not limited to theimplementations so described, but can be practiced with modification andalteration without departing from the scope of the appended claims. Forexample, the above implementations may include specific combination offeatures. However, the above implementations are not limited in thisregard and, in various implementations, the above implementations mayinclude the undertaking only a subset of such features, undertaking adifferent order of such features, undertaking a different combination ofsuch features, and/or undertaking additional features than thosefeatures explicitly listed. The scope of the invention should,therefore, be determined with reference to the appended claims, alongwith the full scope of equivalents to which such claims are entitled.

What is claimed:
 1. A semiconductor device comprising: a substrate; atleast two semiconductor bodies separated from each other by a trench anddisposed over the substrate, the semiconductor bodies having a sourceregion and a drain region separated by a channel region; aresputter-formed contact layer on the semiconductor bodies and formed byre-sputtering an initial contact layer at least partially redistributedto a portion of the semiconductor bodies within the trench so that theresputter-formed contact layer has at least a partial overhang withrespect to one or more sidewalls of the semiconductor bodies; a gatedielectric layer disposed over the channel region of the semiconductorbodies; and a gate electrode disposed over the gate dielectric layer. 2.The semiconductor device of claim 1 wherein the semiconductor bodieshave a top and sidewalls extending from, and transverse to, the top, andwherein the initial contact layer is disposed at least on the top, andthe resputter-formed contact layer is disposed at the sidewalls withcontact material from initial contact layer at the top.
 3. Thesemiconductor device of claim 1 wherein the semiconductor bodies havesidewalls extending from the trench, the trench having a bottom, andwherein the initial contact layer is disposed at the bottom of thetrench, and wherein the resputter-formed contact layer at the sidewallsis at least partially formed from contact material from the bottom ofthe trench.
 4. The semiconductor device of claim 1 wherein the initialcontact layer comprises a sacrificial portion configured and arranged tobe redistributed during re-sputtering of the contact material from theinitial contact layer.
 5. The semiconductor device of claim 4 whereinthe sacrificial portion adds about 10-20 nm to the height of the initialcontact layer.
 6. The semiconductor device of claim 1 wherein thecontact material comprises titanium.
 7. The semiconductor device ofclaim 1 wherein the semiconductor bodies have a top and sidewallsextending transverse to a top, and wherein the resputter-formed contactlayer is disposed at the sidewalls and has a total thickness at thesidewalls of at least about 1-5 nm thick.
 8. The semiconductor device ofclaim 1 wherein the semiconductor bodies have a top and sidewallsextending from, and transverse to, the top, and wherein the initialcontact layer is disposed at least on the top, and the resputter-formedcontact layer is disposed at the sidewalls with contact material fromthe initial contact layer at the top, wherein the semiconductor bodieshave sidewalls extending from the trench, the trench having a bottom,and wherein the initial contact layer is disposed at the bottom of thetrench, and wherein the resputter-formed contact layer at the sidewallsis at least partially formed from contact material from the bottom ofthe trench, wherein the initial contact layer comprises a sacrificialportion configured and arranged to be redistributed during re-sputteringof the contact material from the initial contact layer, wherein thesacrificial portion adds about 10-20 nm to the height of the initialcontact layer, wherein the resputter-formed contact layer is disposed atthe sidewalls and has a thickness at the sidewalls of at least about 1-5nm thick, wherein the contact material comprises titanium, wherein there-sputter-formed contact layer being formed by a plasma bombardmentmaterial directed toward the initial contact layer and on a biasedwafer; and the semiconductor device comprising a spacer disposed at thegate electrode, the contact material being disposed at a surface of thespacer from the depositing of the contact material of the initialcontact layer, and the contact material having a sufficient amount onthe surface of the spacer to form a sacrificial layer at the spacer toavoid damage to the spacer during re-sputtering.
 9. A mobile computingplatform, comprising: a microprocessor comprising: a substrate, at leasttwo semiconductor bodies separated from each other by a trench anddisposed over the substrate, the semiconductor bodies having a sourceregion and a drain region separated by a channel region, aresputter-formed contact layer on the semiconductor bodies and formed byre-sputtering an initial contact layer at least partially redistributedto a portion of the semiconductor bodies within the trench so that theresputter-formed contact layer has at least a partial overhang withrespect to one or more sidewalls of the semiconductor bodies; a gatedielectric layer disposed over the channel region of the semiconductorbodies, and a gate electrode disposed over the gate dielectric layer; adisplay screen communicatively coupled to the microprocessor; and awireless transceiver communicatively coupled to the microprocessor. 10.The platform of claim 9 wherein the semiconductor bodies have a top andsidewalls extending from, and transverse to, the top, and wherein theinitial contact layer is disposed at least on the top, and theresputter-formed contact layer is disposed at the sidewalls with contactmaterial from the initial contact layer at the top.
 11. The platform ofclaim 9 wherein the semiconductor bodies have sidewalls extending fromthe trench, the trench having a bottom, and wherein the initial contactlayer is disposed at the bottom of the trench, and wherein theresputter-formed contact layer at the sidewalls is at least partiallyformed from contact material from the bottom of the trench.
 12. Theplatform of claim 9 wherein the initial contact layer comprises asacrificial portion configured and arranged to be redistributed duringre-sputtering of the contact material from the initial contact layer.13. The platform of claim 12 wherein the sacrificial portion adds about10-20 nm to the height of the initial contact layer.
 14. The platform ofclaim 9 wherein the semiconductor bodies have a top and sidewallsextending transverse to a top, and wherein the resputter-formed contactlayer is disposed at the sidewalls and has a thickness at the sidewallsof at least about 1-5 nm thick.
 15. The platform of claim 9, wherein thesemiconductor bodies have a top and sidewalls extending from, andtransverse to, the top, and wherein the initial contact layer isdisposed at least on the top, and the resputter-formed contact layer isdisposed at the sidewalls with contact material from the initial contactlayer at the top, wherein the semiconductor bodies have sidewallsextending from the trench, the trench having a bottom, and wherein theinitial contact layer is disposed at the bottom of the trench, andwherein the resputter-formed contact layer at the sidewalls is at leastpartially formed from contact material from the bottom of the trench,wherein the initial contact layer comprises a sacrificial portionconfigured and arranged to be redistributed during re-sputtering of thecontact material from the initial contact layer, wherein the sacrificialportion adds about 10-20 nm to the height of the initial contact layer,wherein the resputter-formed contact layer is disposed at the sidewallsand has a thickness at the sidewalls of at least about 1-5 nm thick,wherein the contact material comprises titanium, wherein there-sputter-formed contact layer being formed by a plasma bombardmentmaterial directed toward the initial contact layer and on a biasedwafer; and the platform comprising a spacer disposed at the gateelectrode, the contact material being disposed at a surface of thespacer from the depositing of the contact material of the initialcontact layer, and the contact material having a sufficient amount onthe surface of the spacer to form a sacrificial layer at the spacer toavoid damage to the spacer during re-sputtering.